Farm ventilation is critical for regulating temperature, humidity, and air quality in barns, poultry houses, and greenhouses. AC-powered linear actuators are a robust, cost-effective solution for automating vents, louvers, and windows. Below is a detailed guide on design, selection, and implementation.
✅ High Torque & Durability – Handles heavy-duty vent openings.
✅ Weather Resistance – Works in dusty, humid, and corrosive farm environments.
✅ Simple Power Supply – Connects directly to standard 110VAC/230VAC mains.
✅ Low Maintenance – No compressed air or hydraulics needed.
A. Force & Load Requirements
Static Load (holding force to keep vents open/closed).
Dynamic Load (force to overcome wind resistance, friction, and vent weight).
Typical Force Range: 500 N to 5,000 N (50–500 kgf).
Example Calculation for a Greenhouse Roof Vent:
Vent Weight: 20 kg
Wind Load: 300 N
Friction: 100 N
Total Force Needed: 20 kg × 9.81 + 300 N + 100 N ≈ 500 N
Safety Factor (1.5x): 750 N actuator recommended.
B. Stroke Length & Spee
Stroke: Typically 100–600 mm (adjustable for different vent sizes).
Speed: 5–20 mm/s (slow enough to prevent damage).
C. Duty Cycle & Lifespan
Intermittent Duty (S2): Short, frequent movements (e.g., adjusting vents every 30 mins).
Continuous Duty (S1): For constant modulation (rare in farms).
Expected Lifespan: 50,000+ cycles (industrial-grade actuators).
A. Motor Types
|
Type |
Pros |
Cons |
Best For |
|
AC Synchronous |
High torque, reliable |
Fixed speed |
Basic on/off vent control |
|
AC Gear Motor |
Speed reduction, higher force |
Slightly slower |
Heavy-duty vents |
|
Servo-Controlled |
Precise positioning |
Expensive |
Smart greenhouses |
B. Drive Mechanism
Lead Screw: Self-locking, good for static holds (e.g., keeping vents open).
Belt Drive: Faster, quieter (for lightweight vents).
C. Protection & Environmental Resistance
IP Rating: IP65 (dust/water-resistant) for outdoor use.
Material: Aluminum housing (lightweight) or stainless steel (corrosion-resistant).
Temperature Range: -30°C to +60°C (for extreme climates).
A. Basic On/Off Control
Limit Switches: Automatically stops at fully open/closed positions.
Manual Switches: Override control for emergencies.
B. Smart Farm Integration
Thermostat/Humidity Sensors: Triggers vent opening at set thresholds.
PLC/Controller: For multi-zone ventilation (e.g., Arduino + Relay).
Wireless (IoT): Remote control via Wi-Fi/GSM (e.g., NodeMCU, LoRa).
A. Common Vent Types
Roof Vents (greenhouses) – Linear actuators push/pull vent arms.
Sidewall Louvers – Actuators mounted horizontally.
Curtain Systems – Multiple actuators for rolling sidewalls.
B. Mounting Styles
Fixed-Point Mounting: Pivot brackets for angular movement.
Linear Rail Guides: Ensures smooth motion for heavy vents.
Specs:
Vent Type: Sidewall louver (60 kg, 400 mm stroke).
Force Needed: 2000 N (with safety margin).
Actuator Choice:
Model: 230VAC, 3500 N thrust, IP66.
Stroke: 400 mm.
Speed: 10 mm/s (40 sec full travel).
Control: Thermostat + limit switches.
LINAK (agricultural-grade actuators)
Thomson (Electrak AC)
TiMOTION (heavy-duty farm actuators)
Power Jack Motion (AG series farm actuators)
Lubricate lead screws annually (silicone grease).
Check limit switches for misalignment.
Inspect seals for dust/water ingress.
For most farm ventilation systems, a 230VAC, 750–3,500 N, IP65-rated linear actuator with limit switches and thermostat control is ideal. For smart farming, integrate with IoT sensors (temperature, CO₂).
